/*
 * Copyright (C) 2013 Adrian Ulrich <adrian@blinkenlights.ch>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

package net.nullsum.audinaut.util.tags;

import androidx.collection.LruCache;

import java.util.HashMap;
import java.util.Vector;

public final class BastpUtil {
    private static final RGLruCache rgCache = new RGLruCache();

    /**
     * Returns the ReplayGain values of 'path' as <track,album>
     */
    public static float[] getReplayGainValues(String path) {
        float[] cached = rgCache.get(path);

        if (cached == null) {
            cached = getReplayGainValuesFromFile(path);
            rgCache.put(path, cached);
        }
        return cached;
    }


    /**
     * Parse given file and return track,album replay gain values
     */
    private static float[] getReplayGainValuesFromFile(String path) {
        String[] keys = {"REPLAYGAIN_TRACK_GAIN", "REPLAYGAIN_ALBUM_GAIN"};
        float[] adjust = {0f, 0f};
        HashMap tags = (new Bastp()).getTags(path);

        for (int i = 0; i < keys.length; i++) {
            String curKey = keys[i];
            if (tags.containsKey(curKey)) {
                String rg_raw = (String) ((Vector) tags.get(curKey)).get(0);
                float rg_float = 0f;
                try {
                    String nums = rg_raw.replaceAll("[^0-9.-]", "");
                    rg_float = Float.parseFloat(nums);
                } catch (Exception ignored) {
                }
                adjust[i] = rg_float;
            }
        }
        return adjust;
    }

    /**
     * LRU cache for ReplayGain values
     */
    private static class RGLruCache extends LruCache<String, float[]> {
        public RGLruCache() {
            super(16);
        }
    }

}

